1. Field of the Invention
The present invention provides a parachute of the cruciform-type which is utilized primarily for the carrying of small loads for air delivery of payloads such as weapons and detection devices. The overall size of the canopy of such cruciform parachutes is normally between six inches and fifteen feet in diameter approximately.
Cruciform designs are notable for the low cost. Originally cruciform parachutes were commonly made by laying two fabric panels across one another at right angles and joining them with a cross such as when placed flat on the floor forming a cross symbol.
Furthermore, cruciform parachutes inherently have an inflated shape which enhances stability. This stability is achieved by the natural placement of four large gaps or gores in the canopy. These gores prevent oscillating as the parachute descends in order to enhance the reliability of weapons delivery.
2. Description of the Prior Art
Conventional cruciform parachutes are fine during delivery of air payloads by aircraft moving at relatively slow speeds. However with the increase in speed of such delivery aircraft, problems have developed. In particular, previously used parachutes tend to have problems inflating as well as problems remaining in a normally inflated orientation. These problems result often from the suspension lines which are attached to the center portion of each panel being stretched unevenly and greater than the outer line. This may result in line failure as well as payload loss.
Also, with the introduction of "Kevlar" as the material for the suspension lines, the lines have become much more inelastic which prevents stretching of conventional suspension lines which have heretofore somewhat compensated for the unequal tensions existant thereon.
Examples of patents showing prior art previously used as cruciform parachutes are noted such as U.S. Pat. No. 1,777,441 patented Oct. 7, 1930 to I. V. Malmer on a Parachute; U.S. Pat. No. 2,404,672 patented July 23, 1946 to C. A. Volf on a Vented Parachute; U.S. Pat. No. 2,683,575 patented July 13, 1954 to H. G. Heinrich on a Vented Sector Parachute; U.S. Pat. No. 2,733,028 patented Jan. 31, 1956 to H. K. Epple on a Parachute Canopy Construction; U.S. Pat. No. 2,925,971 patented Feb. 23, 1960 to J. A. Istel et al on a Non-Oscillating, Non-Steerable Parachute; U.S. Pat. No. 3,298,639 patented Jan. 17, 1967 to H. G. Heinrich et al on a Gliding Parachute; U.S. Pat. No. 3,420,478 patented Jan. 7, 1969 to O. B. Ferguson on a Parachute; U.S. Pat. No. 3,531,067 patented Sept. 29, 1970 to J. R. Mitchell on a Parachute and U.S. Pat. No. 3,602,462 patented Aug. 31, 1971 to R. J. Slater et al on a Parachute.